This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Agaric Acid is derived from a fungus, Polyporus officinalis. It paralyzes the peripheral nerves of the sweat glands. It is used to arrest colliquative sweats. Its action is rather evanescent. Maximal single dose is 1/2 grain. Usual dose, 1/8 to 1/4 grain. Do not use it hypodermically. It is listed in N. N. R.
Benzoic Acid, Acidum Benzoicum, both the natural and synthetic acids official. Its chief sources of supply are from benzoin and toluol. A form made from the urine of herbivorous animals should not be employed in medicines or pharmacy. The dose is 5 to 10 grains; its salts twice as much.
Benzoin and benzoic acid can be grouped together therapeutically (Tr. benzoin, average dose 15 minims; compound tincture, twice as much), and no separate description is necessary here.
These agents are antiseptic, a solution of 1 to 1000 of benzoic acid being antiseptic, and 4 to 1000 zymotic as regards many bacteria, but not to all. Do not depend upon it as a zymocide.
Adding antipyretic action to antisepsis, it is a fair substitute for the salicylates, though slower. The sodium salt is used in acute rheumatic fever and in several of the zymotic fevers, even in typhoid and malaria. It is not antipyretic except in septic or zymotic fevers. In my own experience, the doses necessary in rheumatism and other infections must be large to be effective, and, in a sick man, they cause depression with cerebral irritation.
As an external antiseptic the compound tincture of benzoin is more available than is benzoic acid and its salts. In fact, this tincture, in the treatment of chilblains, spongy gums, old ulcers and sinuses, and in tender nipples, should be more generally used.
As an expectorant, there is no doubt that in the chronic form of bronchitis it gives relief to administer various forms of the benzoates, since they influence the septic qualities of the expectorated matter; but the continued administration is most debilitating, as was proven in the "poison squad" tests undertaken to determine if benzoates were proper food preservatives. The terebinthinates are to be preferred. See "Abies." But inhalations of the tincture, or its atomization, may be employed with advantage in laryngeal affections.
In my view, the before-mentioned internal uses of benzoic acid and its salts may be discontinued with little loss to therapy. The substitution of Cinnamic Acid has not helped the situation, since it is rarely effective. Natural salicylic acid is vastly more effective in most of the indications for an internal antipyretic antiseptic.
Genito-urinary uses of the benzoates are upon a better scientific and clinical basis, the ammonium and sodium salts being used. Wherever it is necessary to increase the acidity of the urine, the benzoates are useful, and this is a wide field. Since benzoic acid is eliminated as hippuric acid, except in febrile states, and hippuric acid is an acid natural to the urine and not at all irritating, this use of the benzoates is thoroughly well based. If but small quantities are required to maintain acidity, the free eating of stewed prunes may suffice, for they contain benzoic acid in appreciable amount. Except in aggravated cases, comparatively small doses (5 grains) of the benzoates serve in the genitourinary indications. Hexamethylenamine is a better urinary antiseptic, provided that the urine is not excreted in an alkaline state; when it is alkaline, make it acid with the benzoates, and then hexamethylenamine will be applicable.
I use the benzoates rarely except in the genitourinary indications, believing the tincture and the compound tincture to be more available for the other uses that are really justified.
Camphoric Acid (U. S. P., VIII). Roth, in an elaborate paper,1 showed the action of this acid to be due to salt action, its only well marked physiological action being its stimulation of the central nervous system resembling that of camphor. It possesses no paralyzing action upon the nerve ends in the sweat glands, as does atropine. But, as Kobert stated, sweats incident to phthisis are asphyxial in origin and due to a depression of the respiratory center. So, then, both camphoric acid and picrotoxin are useful in the night-sweats of pulmonary tuberculosis.
Give it dry on the tongue in doses of 15 grains an hour or two before the sweating is due to occur.
Citric Acid (U. S. P.). Citric and Tartaric acids are refrigerants. In the alimentary canal they are converted into alkaline citrates and tartrates, are absorbed, and excreted in the urine as carbonates, making the urine alkaline. Citric acid is given in doses of 5 to 15 grains; but lemons, limes, oranges, and grape-fruit are commonly used in its place. Tartaric acid is rarely used. Citrus fruits antagonize urinary acidity, scurvy, and certain fevers.
Gallic Acid (U. S. P.) is much weaker than tannic acid, and does not coagulate albumin, as does tannic acid. It possesses no advantages for internal administration and it is very doubtful if it possesses any astringent action upon parts it reaches through the circulation. Pyrogallic Acid is an irritant antiseptic sometimes applied externally in chronic skin diseases, 1 to 8 of lard; but it has been absorbed from the surface with fatal results. Bismuth Subgallate is given in 2- to 8-grain doses. Its real use is, either in official form or as Dermatol, as a dusting powder. It is little liable to absorption.
1 "An experimental study of Camphoric Acid," Jour, of Pharmacology and Exper. Ther., May, 1011.
Salicylic Acid - Natural. This acid is derived from the natural oils of wintergreen and sweet birch. As at first made, the synthetic salicylic acid was impure, containing cresylic acids. These were later removed by improvements in processes. Then it was stated that cresotinic acids exist in the synthetic product, which is stating much the same thing in another way. Now as a matter of fact, the synthetic acid can be entirely freed from these impurities and the resultant acid have exactly the same chemical formula as has the natural acid, and doubtless some of the purer grades of the synthetic acid are marketed quite free from these slowly paralyzant impurities.